Can Demerol Be Taken Instead Of Morphine?

I am having surgery tomorrow and have requested Demerol instead of Morphine. I have not had any pain medication for many years, the last time they gave me Morphine in the OR I was very disoriented and it gave me a headache. Is it okay to request a pain medication without sounding like an addict. I am very health take no medication. The surgery is a feminine thing.